Casey Case Study

1. Children were sat in an empty room with 1 marshmallow on a table, they were told if you wait till I come back and not eat this then you can have another but if you've eaten it when i ge back you can't

1. The ability to resist temptation for an immediate reward and wait for a later reward

1. Cues that we find neutral. They are not particularly appealing (eg shapes)

1. Cues that are tempting and appealing to us(eg the chewy, sweet taste of a marshmallow)

1. Focussing on the cool cues to reduce temptation (eg envisaging the marshmallow as a ball of cotton wool)

1. 59 Particpants
   1. 22 High Delayers
      1. 12 Male, 20 Female
   2. 27 Low Delayers
      1. 11 Male, 16 Female
2. Of the 135 P's who took part in their 30's, She wanted those who had been consistently low delayers and high delayers
3. Opportunity

1. Go/No-Go task- using cool and hot stimuli
   1. Go=Push button, No Go= Don't Push button
   2. Cool Task
      1. Cool Stimuli=Neutral faces
      2. 32 High Delayers, 27 Low Delayers
      3. 120 Go trials
      4. 40 No-Go trials
      5. Male Go/Female No-Go= P's saw pictures of male and female neutral faces. Had to press a button when a male face appeared
      6. Female Go/Male No-Go= P's saw pictures of male and female neutral faces. Had to press a button when a female face appeared
   3. Hot Task
      1. Hot Stimuli= Happy faces
         1. 'Alluring'/tempting to adults in the same way marshmallows were to a 4 Yr old
      2. 120 Go trials
      3. 40 No-Go trials
      4. Happy Go/fearful No-Go=P's saw pictures of male and female faces which some and smiling and some are fearful.Had to press a button when a happy face appeared(120 times)
      5. Fearful Go/Happy No-Go= P's saw pictures of male and female faces which some and smiling and some are fearful.Had to press a button when a Fearful face appeared(120 times)
2. Task Procedure
   1. P's were tested individually, completed test on a laptop that was sent to their home
   2. Ps took part in an impulse control task ('Go/No Task')
   3. P's told that they will be shown a series of male and female faces which will appear for 500m/s
   4. P's are instructed to push a button every time a certain type of face appears
   5. P's were told to complete the task as quickly and accurately as possible, their reaction times and accuracy were recorded
   6. Every time a face flashed up this was 1 'trial'
   7. Each P did 4 sets of 160 trials(2 Cool versions, 2 Hot versions)
3. Repeated measures design

1. Reaction times on the Go trials
   1. There was no difference in the reaction times of the two groups, the high delayers and the low delayers
2. Accuracy
   1. Go Trials- Similar levels of accuracy were found between the low and high delayers, accuracy was very good
   2. No-Go Trials-Both groups made more errors on the No-Go trials
   3. Cool task
      1. Both groups made a similar number of errors on the cool task
   4. Hot Task
      1. Low delayers performed worse than high delayers but this was not statistically significant (p=0.11)
      2. Fearful Face- High and Low delayers made similar numbers of errors
      3. Happy face- Low delayers made significantly more errors than the high delayers
   5. High Delayers on both tasks
      1. The number of errors the high delayers made was similar for both tasks
   6. Low Delayers on both tasks
      1. Made significantly more errors on the Hot task than the Cool task (P=0.005)

1. Low delayers who had shown more difficulty in delaying gratification at age 4 show more difficulty suppressing responces to happy faces in their 40's
2. Low self-control remains constant in an individual
3. Depends on the rewarding nature of the stimulus as the low delayers had more difficulty on 'fearful face=Go trials' than the high delayers did

1. 27 Participants
   1. 15 High Delayers
      1. 5 Males, 10 Females
   2. 11 Low Delayers
      1. 7 Males, 4 Females
   3. 1 Man excluded from analysis due to poor performance task to make a total of 26 P's
2. Opportunity

1. Same 2 'Hot' Go/No-Go task whilst having their brain scanned to examine what ares of the brain are associated with self-control
   1. Used an fMRI (investigates the anatomy of the brain-its structure) to scan P's brain
2. 48 trials in each run(set of faces), total of 96 trials
3. Each face appeared for 500 m/s with mean 5.2 sec delay

1. Reaction Times
   1. No differences between the 2 groups
2. Accuracy
   1. Go Trials;Similar levels between both groups
   2. No-Go Trials; Low Delayers performed worse than high delayers but was not significant
3. Imaging results
   1. Inferior frontal Gyrus
      1. Low Delayers had lower activity here than the High Delayers
         1. Suggests this brain region helps us to withhold a responce and not to give into temptation, the high delayers found it easier to delay their gratification as the IFG was more active then the low delayers
   2. Ventral Striatum
      1. Low delayers had higher activity here than the high delayers
         1. Low delayers are more drawn to alluring stimuli (smiling faces) and found it harder to resist(to not press the button in the No-Go trials)

1. Confirms there is a difference in brain activity in key areas relating to resisting temptation between high and low delayers
2. Low delayers' right inferior frontal gyrus (cognitive decision making) is less active on No-Go trials and there is more activity in their ventral striatum (emotion and desires)

1. 'Hot' system is controlled by the Ventral Striatum
2. 'Cold' system is controlled by the Inferior Frontal Gyrus

1. All ethical guidelines upheld
   1. Informed consent, No deception, No harm caused, Right to withdraw shown in P's who took part in Expt 1 but not Expt 1

1. Internal
   1. The procedure and instructions were standardised and parts of Expt 1 were replicated in Expt 2 due to controlled conditions
2. External
   1. The sample was large enough to suggest a consistent effect (+25)

1. Internal
   1. High Design Validity due to high controls
   2. She used scientific equipment (fMRI) to increase the accuracy of the results
2. External
   1. Population
      1. Not Generalisable compared to the sample in Expt 1
   2. Ecological (EV)
      1. Low EV; Contrived tests so the findings won't tell us how people respond under normal conditions
         1. fMRI not used in everyday life

1. Not Ethnocentric
   1. Investigates a species specific behaviour
2. Ethnocentric
   1. Research only conducted in America, temptation may be affected by culture and we should be cautious assuming lack of self-control is 'natural' or a 'universal human trait'

Annotations:

• Need to explain these

1. Nature-Nurture
2. Freewill-Determinism
3. Usefulness
4. Psychology as a science

1. Investigates whether there are specific regions of the brain that impact on our ability to resist the temptation of rewarding stimuli

1. Reveals that there are 2 regions of the brain that have an impact on our ability to resist temptation and defer gratification